stagefright: stop audio source if player fails to start

Change-Id: I70083f8bfe8409283e52eea017d27d94767c5244
stagefright: Move to 64 available tracks

Many games use numerous tracks.  If the system
runs out of tracks, new tracks won't be able
to be created.  This has been causing notifications
not to play if many apps are holding open tracks.

Issue: BACON-6

Change-Id: I9cea51b9bd678feba31a88e17dd22083b01d81de
Merge "stagefright: Move to 64 available tracks" into du44
cameraservice: Resolve message vs start/stop preview races

Move the mutex in start/stopPreview to include the metadata message
management. Fast start/stop sequences could (and would) eventually
cause the messages to be enabled/disabled out of sequence (or while
the camera wasn't ready for it)

Fixes BACON-173

Change-Id: I367bc45729ce2e858fea972f35e881a755c6021a
Merge pull request #2 from DirtyUnicorns-KitKat/du44

merged